De Natura Deorum Libri Tres
by Marcus Tullius Cicero

Introduction

Cicero's essay on the nature of the gods is at once
our most accessible and most complete original authority on the theology of the ancients;
it gives us a brief outline of the views of the older thinkers and a complete exposition
of the doctrines of those schools of philosophy which in later times included the greater
number of educated people.The treatise consists of four parts: first, a brief sketch
of the most noteworthy opinions on the subject from the beginning of philosophic
speculation down to the complete development of the Epicurean and the Stoic systems;
second, a detailed exposition of the Epicurean, and third, of the Stoic philosophy;
fourth, a criticism of both these systems from the standpoint of the Academic scepticism.The book opens with a dedication to M. Junius Brutus,
afterwards the murderer of Caesar, a man whose finished philosophical culture and writings
are often mentioned with the greatest deference by Cicero, who was himself twenty-one
years his senior. Excellens omni genere laudis, he says of him in Acad. I, 3, 12, ac
philosophiam Latinis litteris persequitur, nihil tit iisdem de rebus Graecia desideret. He
professed the doctrines of the Academy of Antiochus. We have none of his works remaining;
but Seneca, Consol. ad Helv. ch. 9, quotes a short passage from his book De Virtute, and
Quintilian, X, 1, 123, says that in his philosophical writings he was egregius multoque
quam in orationibus praestantior; and further suffecit ponderi rerum; scias eum
sentire quae dicit. Besides the books De Natura Deorum Cicero dedicated to him De
Finibus, the Tusculan Disputations, the Paradoxa and the Orator; and
called by his name the book De Claris Oratoribus, where Brutus is one of the
speakers.
The date of writing this book may be determined, if not with entire
certainty, yet with the greatest probability. That it was written before the murder of
Caesar, that is before the Ides of March, 45 B.C.E., follows without any doubt from the
manner in which Caesar's supremacy is spoken of in I, 4, 7; and that Cicero was occupied
upon it in the summer of 44 B.C.E. may be inferred from the letter to Atticus written in
June of this year (XIII, 39, 2), where he asks him for the book of Phaedrus peri theon
doubtless to make use of it in the composition of this book. - But the greater part of
Cicero's philosophical works, the Academica, De Finibus Tusculan Disputations, De
Divinatione, De Fato, De Senectute, De Officiis, De Amicitia, and the De Universo or
Timaeus, a translation of that of Plato, among those which are wholly or in part
extant and the De Consolatione, Hortensius, De Gloria, and perhaps De Virtutibus
among those which are lost with the exception of a few fragments, were written in the
short interval between the spring of 45 and the autumn of 44 B.C.E., in the sixty-second
and sixty-third years of his life; and while we are astounded at a literary activity of
such extent, we learn, partly from the prefaces to these treatises and partly from the
letters to Atticus, the occasion of writing them, and Cicero's state of mind at the time. Hortata
est, he says, N. D., I, 4, 9, ut me ad haec conferrem, animi aegritudo, fortunae
magna et gravi commota iniuria, cuius si maiorem aliquam levationem reperire potuissem non
ad hanc potissimum confugissem. This hard stroke of fortune alluded to was the death
in March, 709 A.U.C. (45 B.C.E.), of his daughter Tullia, his favorite child, to whom he
was most tenderly devoted, and whose loss afflicted him most deeply. He expresses his
state of mind in a letter to Atticus (XII, 14, 3), written in March 709 A.U.C.: Nihil
de maerore minuendo scriptum ab ullo est, quod ego non legerim; sed omnem consolationem
vincit dolor. Quin etiam feci, quod profecto ante me nemo, ut ipse me per litteras
consolarer. Affirmo tibi nullam consolationem esse talem. Totos dies scribo, non quo
proficiam aliquid; sed tantisper impedior, non equidem satis, - vis enim urget, sed
relaxor tamen enitorque ad animum reficiendum. There was no opportunity, as public
affairs were at the time, for him to engage in them with dignity and success, and so
obtain relief from his sorrow; and this condition of the state itself for a man like
Cicero was no less a source of sadness, than his own domestic grief.When we consider these circumstances we are little disposed
to pass a strict judgment on Cicero's philosophical works, but rather to excuse many
undoubted shortcomings in an old man afflicted and borne down by sadness and care. Even a
philosopher by profession would hardly have been able in such a state of mind and in so
short a time to write satisfactorily upon all the most difficult problems of philosophy at
such length; how much less a man, who, however earnestly he had studied these subjects,
was really only a dilettante; and who for the larger and better part of his life had been
occupied as a statesman and an advocate with great activity and brilliant success. His
philosophical writings are in fact little else than translations or extracts from Greek
predecessors; and we should not wonder at many misunderstandings or other traces of haste
and carelessness. These defects must not however prevent us from a thankful recognition of
Cicero's merits even as a philosophical writer. He was the first to develop the Latin
language so as to make it fit for the treatment of philosophical subjects; more than any
one else he promoted and made easy the pursuit of these studies for his countrymen; and
finally we owe to him an acquaintance with many portions of the ancient philosophy of
which we should otherwise be quite ignorant; and however disparaging the judgment of many
people nowadays, no one can deny the importance of these works for the history of
philosophy.

Visitors may read the full
Introduction which discusses the relative strengths and weaknesses of the various
philosophical and religious ideas that Cicero presents in De Natura Deorum. However keep
in mind that the various conclusions reached by the editor are in fact almost 120 years
old, and that much evolution in philosophical and religious arguments has occurred between
then and modern-day.